The use of propellers is to provide jet propulsion employing the power of air or water flow to drive electric generator or for driving mechanical work (e.g., windmills). Types of propellers include spiral-shape propellers, wing-blade-type propellers. The present invention features a screw propeller system for use in a watercraft. The screw propeller system comprises two or more screw propellers, wherein the screw propellers comprise a tube hub and a spiral blade attached to the tube hub, wherein the screw propellers are disposed on the hull of the watercraft. In some embodiments, the screw propeller system is used in an aircraft or a power plant.
Any feature or combination of features described herein are included within the scope of the present invention provided that the features included in any such combination are not mutually inconsistent as will be apparent from the context, this specification, and the knowledge of one of ordinary skill in the art. Additional advantages and aspects of the present invention are apparent in the following detailed description and claims.